<!doctype html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        .img-wrap {
            width: 100vw;
            height: 100vh;
            margin: auto;
            display: flex;
            align-items: center;
            justify-content: center;
        }

        .img-preview {
            position: absolute;
        }

        .mask {
            position: absolute;
            width: 180px;
            height: 300px;
            border-radius: 50%;
            z-index: 1;

            filter: blur(30px);
            transform: rotate(30deg);
            transition: all 1s;
            box-shadow: 0 0 0 2000px rgba(0, 0, 0, 0.9);
        }
    </style>
</head>
<body>
<div class="img-wrap">
    <img class="img-preview" src="../img/background/small/1：00.png" alt="">
    <div class="mask"></div>
</div>
</body>
</html>
